The Miraculous Stephen Jackson

Today’s post is another joint effort with Josh Weil (@joshweil) from Everything and Nothing. Josh was great about running the data for this piece and if you’re a fan of High School Win Score numbers, you should check out his latest!

I do love the “Miracle of Wages of Wins” that infected Stephen Jackson when he went from a loss leader to all star caliber when he switched teams last season. Im shocked it happened. Not shocked it wasn’t mentioned.

I asked Josh Weil, who has been doing game by game analysis with data from nerdnumbers.com, for a favor and he provided the following graph for S-Jax!

Now, it’s true the Stephen Jackson was absolutely terrible in Milwaukee. It’s also worth noting that Stephen Jackson was 33 last year and players over 30 tend to decline, which is what we’ve been seeing.

In San Antonio, Stephen Jackson did have a resurgence and played the best he had in years. But let’s note a few things:

Stephen Jackson was still below average in San Antonio and had more below average games than “All-Star” level ones.

Finally, Stephen Jackson only played 500 regular season minutes with the Spurs and and only 300 in the playoffs. This isn’t the largest period of time.

Here’s something fun to note about Stephen Jackson’s improvement. Out of 20 games, he had four All-Star level games. If we take these games out, guess what? Jackson’s WP48 for his time on the Spurs drops to 0.000 (which is terrible)

Of course, it takes skill to play an All-Star level game right? All of Jackson’s top games were over 20 minutes. I looked for players that managed to play over 10 games at 20+ minutes and hadn’t managed to put up an All-Star level game. The list only had two names;

It turns out there can be downright terrible players that can still put up more than a few great games.

Summing up

Stephen Jackson has been a sub-par player his entire career. He went to a team with one of the few good coaches/systems that improves players. In a short span he was able to put up a few great games that upped his general level. Of course, any player can play great in the NBA. In fact, almost all players that get decent playing time do.

One last point is this. Mark Cuban, in a slightly aggressive tone, impled that Wins Produced is not perfect. Guess what? He’s right! The box score has a ton of data. It can explain ~95% of wins and much of that can be assigned to individual players. What’s more, players are fairly consistent year to year. This doesn’t mean basketball is solved. It just means we’re darn close.

A criteria was set up (Is there a relationship between offensive rebounds and defensive efficiency?)

And an answer was found (no, not really)

In a league with hundreds of players, the simple fact is not all of them will adhere to a model. That’s fine. The question is: how good is the model you’re using? If we focus on things like the eye test and outliers, we’ll never adequately answer that question. I hope Mark Cuban, who is a supporter of the Sloan Analytics Conference, agrees with this take. After all, all of us are looking for the answers in the stats. We just have to ask the right questions.

24 Responses to "The Miraculous Stephen Jackson"

Putting Diaw up there as an example of a terrible player with great games is a little misleading, because he too had a complete turnaround upon joining the Spurs. Of course, I would say in his case that’s more due to Parker than Popovich.

I do not understand your evidence given for Stephen Jackson’s improvement.

“Stephen Jackson was still below average in San Antonio and had more below average games than “All-Star” level ones.” This is irrelevant. Mark Cuban may have exaggerated when claiming Stephen Jackson was all star caliber; however, his average still increased by 0.184, unexplained improvement almost equivalent to what you would say is all-star level.

“Out of 20 games, he had four All-Star level games. If we take these games out, guess what? Jackson’s WP48 for his time on the Spurs drops to 0.000 (which is terrible).” So 20% of the sample, all on one side, qualifies as outliers?! I don’t understand how it’s fair at all to try removing this data.

Perhaps the biggest reason for the improvement is the fact that WP doesn’t properly allocate defense the way it claims it can. It divides team defense according to minutes. Stephen Jackson goes to an already-great defense team, and what do you know…

If you are catching Nets preseason games, Blatche seems completely changed as well. Players don’t change very often. However, I’m sure many players can improve their WP score by having drilled into them the concept of a good shot versus a bad shot. A player like Blatche has tremendous room to improve in that area, so a coach could make a difference. The Spurs, where all the players are fairly disciplined, could set players up to take good shots resulting in substantial WP improvement even if the player’s individual strategy hasn’t changed.

thank you for the additional data. You actually make my point.
In a team game if one out of every 5 games a player can have a significant, positive impact on the outcome of a game is that player more valuable than the steady state average player ?
If a player plays below WOW average 4 out of 5 games , could this player still be more important to a team than the player that plays at an average level all the time ?
Yes. Matchups and Coaching matter. If you play to your teams strengths and leverage the advantages you have, the player may not be the star of the game every game, but if he can win you the games where he has the advantage , he is doing his job well.

Again, coaching matters. If you force a guy to do what he is not capable of doing you get turnovers, fewer rebounds, missed shots. All WOW negatives.

Finally, when matters. i like advanced +/- is because it weights the event. ie, A rebound or turnover up 15 w 1 min to go shouldnt count.

Players are human beings, not just statistics. This may explain the Popovich effect, as well as the Jackson (Phil, not Mark) effect.

Both coaches have the ability to get their players to stop doing dumb things. But they’re probably not the only coaches who realize that long 2s are bad shots. They’re just the only coaches with the gravitas to make that stick with their players.

I’d be curious if their ability to improve their players showed up in their first few (pre-Championship) years of coaching.

ccagrawal,
“Perhaps the biggest reason for the improvement is the fact that WP doesn’t properly allocate defense the way it claims it can” – Not sure we ever made any such claim. I’d love to continue this discussion but I actually have a prerequisite. Can you explain how WP deals with defense?

Mark,
The people I’ve found that get this stuff the best are gamblers. Players are weighted dice. Josh’s recent work has been great – http://joshweil.blogspot.com/2012/09/share-your-knowledge.html. This completed falls into expected value territory. If a player gives you a bunch of bad nights, is it worth the few good nights they give you? (You didn’t re-sign Odom, who falls into this)

Now again, you’re bringing up stuff that matters. We’ve never disagreed. I will in fact point out your initial point completely ignored both Stumbling on Wins and Arturo’s recent post on coaching, both of which say – Greg Popovich is one of the few coaches that significantly improves players! The real test of these assertions is: how much? Now, I’m sure you have data on this you’re keeping close to the vest. But in an argument on a blog, it’s too nebulous to just say: “Well this matters!”

Finally, I just can’t give much credence to advanced +/-. It’s too noisy. Data is only half the battle. What it tells you matters too. It doesn’t matter if you like the story behind the theory, the data has to back it up. http://www.youtube.com/watch?v=b240PGCMwV0

It would seem natural to me that Captain Jack was more motivated in San Antonio and this could have helped him as much as the system. It’s very clear that Jackson was a more valuable player in San Antonio, whether that’s from the system or him being re-energized. While I don’t use WP, I believe the idea of Jackson getting better going from MIL to SAS doesn’t necessarily go against WP that much, since situations like Jax or Salmons getting a lot better during his first stint in Milwaukee, maybe for mental reasons, are pretty rare

It’s a long-standing truism that all statistics break down in the particular. That can be extended to models/metrics based on statistics. The criticism that Mark extends doesn’t hold water because he’s saying that a particular player’s statistics don’t conform to various models of certain phenomena in the NBA, which he lumps together under the name “WOW”. While outliers may in some cases give you information about failings of particular models, you can not determine what that information is without discovering and describing what is special about the outlier. After you’ve done that, you can see if taking into account any unique characteristics of the outlier improve the model, or if it turns out to be noise. It is not enough to just say “hey, there’s an outlier over here, the model is broken”.

i think if we look at how Stephen Jackson was used by the Spurs, everything makes much more sense. if you look at his box score stats (especially in the playoffs), you find that most of his value-added came from 3 pointers. and if we watch games, what is Stephen Jackson doing? on offense, he mostly sits in the corner – and nothing else.

well, he does have a stroke when he’s selective about his shot, so we shouldn’t be surprised that when put in a disciplined system like Poppovich’s which doesn’t need him to win, necessarily, we get good results.

Andres, I apologize. After rereading my initial post, it sounded much more hostile than I intended. But I would very much like to continue the discussion over WP’s incorporation of defense. I just don’t understand how using the team defense adjustment is fair because it gives Amare the same adjustment as it gives Tyson Chandler, when they’re both certainly not equally deserving.

Also, I have another thought. I could see how playing under a solid coach influenced Stephen Jackson to take better shots, but could you perhaps also attribute this to playing with a better team? His teammates are better and command more attention, freeing up Stephen Jackson and giving him easier opportunities to score than previously. Just a thought.

Dre, this is off topic but all of these posts by mark have me thinking about an older post where mark commented that WOW implied the mavs should giv playing time to bwright and bench dirk, which in his mind is a joke. But should they? Inquiring minds want to know! That would be a provocative post!

The comments on variance are interesting. As a general rule, the better your team is on average the more you want to control variance, and vice versa. That is, bad teams want a lot of randomness so that they can get more random ‘oops I win’ victories, while good teams want consistent, tight play so they don’t have so many random ‘oops I lose’ games.

Also, keep in mind that while in the long run a player’s ability should mesh very well with observable outcomes, in the short run there’s an enormous amount of noise in the data. While WP48 gives a number to describe a player’s performance, it could also come with error bars around it representing your confidence in that number being representative of a long term trend.

I haven’t done the heavy lifting on game to game variance and confidence intervals on minute totals, but just eyeballing that data I’d wager that Jackson|2012|Spurs and Jackson|2012|NotSpurs wouldn’t pass a 95% confidence T-test for being distinct populations.

Coaching could theoretically be the most important determinant in winning games, but if all NBA coaches are of approximately equal ability, then none of them would have any positive/negative impact on players despite being critically important to the success of their team.

So when someone says a coach has to be able to do this, that, the other thing etc.. well or the team will fail, he might be right. It just adds no value because every coach does this, that, or the other thing well.

A better test would be to make ME an NBA coach and see if I could screw up the Heat. :-)